1. Field of the Invention
The present invention relates generally to an electrical connector for terminating armored cables and, more particularly to a connector having a novel armor stop member for properly positioning the cable end within the connector body.
2. Description of the Related Art Connectors used to terminate jacketed armor cable, also known as MC (metal clad) cable in the electrical industry, are made having the conductive wire(s) protected with a metal jacket and the metal jacket covered within a jacket of plastic as a waterproof outer cover. The cable""s metal jacket is designed to protect the conductors and the plastic jacket is made to protect the armor and conductors from moisture. A connector used to terminate this type of cable must perform several functions. One function is to mechanically hold the armor and jacket to support the cable to a terminal box. Another function is to protect the terminal box from moisture by providing a moisture barrier around the knockout and cable jacket. The connector also mechanically terminates and houses the end of the jacket and armor. It is also important to establish a ground connection between the armor and the connector. To do this the armor end of the cable must be positioned accurately within the connector. An example of such a connector is disclosed in U.S. Pat. No. 4,647,934 issued to Hurtt.
Usually the manufacturer of the connector specifies that the jacket and armor be cut allowing enough length to terminate the conductors. In addition they also specify the length of the plastic jacket to be stripped form the end of the armor. A physical relationship must be established to locate the cable""s armor end within the connector so that a ground connection can be made usually with a conductive spring. Most connector designs have an armor stop inside the body which has an opening large enough to pass the conductors through the connector but not allow the armor to pass thus acting as an armor stop. This locates the armor end within the connector preventing the armor end from being pushed through the fitting. It also positions the armor and jacket allowing the ground connection to be made usually by tightening a gland grounding nut(s).
Most connectors are designed to cover a large range of cable sizes. Some cables within the desired armor range have diameters too small to stop cable with small armor diameters. For this reason manufacturers supply an additional wire stop to locate the armor against the armor stop built within the connector thus extending the armor cable range.
This causes several problems for the user installing the connector because the separate armor stop may get lost. Also, when installing the armor stop the stop may be dropped or lost. The decision has to be made whether to use the separate armor stop. To do this the installer has to refer to specifications supplied on an instruction sheet supplied with the fitting, which may specify the range of the separate armor stop. He then has to measure the armor diameter and decide whether to use the separate armor stop or not. This is especially true when the armor stop is assembled within the connector, a common practice. If the installer decides not to use this armor stop assembled within the connector the installer must remove it, typically by disassembling the nut, gland and grounding spring.
After the MC cable is positioned within the fitting, with or without the second armor stop, the gland nut is tightened compressing and securing the cable. If the grommet turns it will put a twisting force on the cable which could turn the cable during the installation process. This results in the twisting of the cable and its conductors during installation. To prevent the grommet from turning and twisting the conductors a friction washer is usually placed between the nut and grommet to reduce the turning forces. This is usually made from a material having a low coefficient of friction such as nylon.
The present invention improves over the prior art by providing an electrical connector assembly for terminating a free end of a metal clad cable comprising a body member and having an end nut. A combined friction washer/armor stop is positioned beneath the end nut. By forcing the free end of a cable against the combined friction washer/armor stop a central stop portion of the friction washer/armor stop breaks free and passes into the body member whereupon it abuts an internal shoulder of the body member thereby properly positioning the cable end within the connector assembly.